Specifications

15xx-A1 Family Router Users Guide 41
Other types of NAT have restrictions such as the sending IP address must initially have
had packets sent from the private IP address and port regardless of the external port, or
from the private IP address and the external port.
Enable NAT must be checked for Fullcone NAT to be used.
 Dial on demand: When this mode is selected, the connection that has no traffic within
assigned disconnect timeout (e.g. 1 minute) will be automatically disconnected. The
connection will be activated again when traffic arrives. This function is advantageous for
users who are charged with online time. It should be noticed that some programs
automatically link to Internet. Computer will send data to network when infected by virus.
Connection will not be disconnected under these data streams.
 Inactivity Timeout: When “Dial on demand” is selected, this input box indicates that
after how long the connection will be disconnected in the absence of traffic. If the value is
0, connection will not be disconnected.
 Enable manual MTU set: the Maximum transmission unit (MTU) value may be set for
your needs. Higher MTU can provide for a more efficient link because each packet will
carry more data while the overhead in the packet such as header information does not
get larger with the size of the packet. So the bulk throughput on the link will go up.
Generally a large packet size can occupy the time on the link, so the higher MTU can
increase lag time and minimum latency which is not appropriate for all applications.
 Manual Connect: connect/disconnect PPPoE connection manually
 Enable NAT: To define NAT services in the Advanced Setup | NAT screens, NAT must
be enabled.
 Enable Firewall: Enables Firewall.
 Use Static IPv4 Address: Defines a static IP address (v4) which you enter in the IPv4
Address text box which is displayed when the Use Static IPv4 Address check box is
selected.
 Enable PPP Debug Mode: Used to debug PPPoE issues. Use only when instructed by
your ISP.
 Enable KeepAlive: Enables/disables TCP keep alive packets
 Enable IGMP Multicast Proxy: Configures the router for IGMP snooping so the router
can keep limit multicast traffic.
6. On the Routing — Default Gateway page set the priority of WAN interfaces used as default
gateways then click Next
If multiple WAN interfaces are configured, you can define the priority by their position in the
Selected Default Gateway Interfaces window. Top is the highest priority; bottom the
lowest.
Change the priority order by removing all items from the Selected Default Gateway
Interfaces window by selecting them, then clicking the right arrow button. Select the items in
the priority order, then click the left arrow to move them into the Selected Default Gateway
Interfaces window.
7. On the DNS Server Configuration page set the priority of WAN interfaces to be used as
DNS server interfaces then click Next
If multiple WAN interfaces are configured, you can define the priority by their position in the
Selected DNS Server Interfaces window. Top is the highest priority; bottom the lowest.
Change the priority order by removing all items from the Selected DNS Server Interfaces
window by selecting them, then clicking the right arrow button. Select the items in the priority
order, then click the left arrow to move them into the Selected DNS Server Interfaces
window.
For a Static DNS IP Address, enter a primary and secondary DNS server for your modem,